On 05.02.2016 14:07, Prof Brian Ripley wrote: > sysctl on 10.11 has options which would enable us to differentiate > between logical and physical codes on parallel::detectCores --- however > these are not documented in Apple's online man pages, which are for > 10.9. Could someone running 10.9 and someone for 10.10 report if > > /usr/sbin/sysctl -n hw.physicalcpu > /usr/sbin/sysctl -n hw.logicalcpu > > run in a terminal work and gives the correct result? (Normally the > second will be twice the first taking account of hyperthreading.) Here is the output for an older OS X version, 10.7.5. The computer has a dual core processor without hyperthreading. Also included is the listing of all sysctl variable names that begin with "hw." and are followed by something with "cpu".
The man page about the command line tool, sysctl(8), does not mention hw.physicalcpu or hw.logicalcpu. However, the variables are listed on the man page sysctl(3), which is about the underlying C functions. The latter man page was apparently installed with the XCode Command Line Tools package. Therefore I have also printed its version number. $ /usr/sbin/sysctl -n hw.physicalcpu 2 $ /usr/sbin/sysctl -n hw.logicalcpu 2 $ sw_vers ProductName: Mac OS X ProductVersion: 10.7.5 BuildVersion: 11G63 $ /usr/sbin/sysctl -a | grep "hw\\..*cpu" | sed 's/[: ].*//' hw.ncpu hw.cpufrequency hw.availcpu hw.ncpu hw.activecpu hw.physicalcpu hw.physicalcpu_max hw.logicalcpu hw.logicalcpu_max hw.cputype hw.cpusubtype hw.cpu64bit_capable hw.cpufamily hw.cpufrequency hw.cpufrequency_min hw.cpufrequency_max $ pkgutil --pkg-info=com.apple.pkg.DeveloperToolsCLI | grep version version: 4.6.0.0.1.1365549073 -- Mikko Korpela Aalto University School of Science Department of Computer Science _______________________________________________ R-SIG-Mac mailing list R-SIG-Mac@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-mac